Review of the C Language

3. The code of the program conditions.c:

   /* A C program that shows how condition
    *    statements (if, if-else, if-else-if,
    *    and switch) work.
    *
    *    Miriam Briskman, 2/8/2023
    *    CISC 3350, Brooklyn College
    *    Licensed under CC BY-NC 4.0
    */
   
   #include <stdio.h>
   #include <stdlib.h>
   
   int main ()
   {
       unsigned int salary = 58700;
   	
       // If statement (if the condition is true,
       //    execute the statement that follows)
       if (salary >= 50000)
           printf ("This is a middle-class person.\n");
   
       // If-else statement (if the 'if' condition
       //    is false, execute the statement that
       //    follows the 'else':)
       if (salary < 32320)
           printf ("Below NYC's average salary.\n");
       else
           printf ("Above NYC's average salary.\n");
   
       // If-else-if statement:
       if (salary < 40000)
           printf ("Tax of 20%%.\n");
       else if (salary < 50000)
           printf ("Tax of 25%%.\n");
       else if (salary < 60000)
           printf ("Tax of 30%%.\n");
       else
           printf ("Tax of 35%%.\n");
   
       // Follow-up question:
       // Which salaries fall into the last
       //    'else' statement above?
   
       // [Note the double %% above. Since % is used
       //  to denote format specifiers like %d, it
       //  means that % is an escape character. To
       //  print the percentage sign on the screen,
       //  we need to escape %, which we do with
       //  %%.]
   
       // *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
   
       char letter_grade = 'B';
   
   	
       /* Switch statements are efficient alternatives
             to if statements in the cases that we want
             to check for the equality of a variable to
             some value/number.
          In C, switch statements can work with char
             variables and with integers of all kinds!
       */
   
       printf ("The letter grade of %c indicates that "
               "the student ", letter_grade);         
   
       switch (letter_grade)
       {
           case 'F': printf ("Failed!\n"); break;
           case 'A': printf ("Excellently ");
           case 'D':
           case 'C':
           case 'B': printf ("Passed!\n"); break;
           case 'W': printf ("Withdrew!\n"); break;
           case 'P': printf ("Passed!\n"); break;
           case 'U': printf ("Unsatisfactory!\n"); break;
           case 'S': printf ("Satisfactory!\n"); break;
           default:  printf ("Error: this letter doesn't "
                             "correspond to any grade!\n");
       }
   
       // Follow-up question:
       // In the 'default' case above, why
       //    isn't there a need to use the 'break;'
       //    statement?
   
       return EXIT_SUCCESS;
   }